Electronic apparatuses, such as mobile terminal apparatuses, for example, have become increasingly multi-functional. For example, some of mobile terminal apparatuses are capable of performing various kinds of information processing, such as voice communication, document creation, access to a Web site, transmission and receiving of an email, playback of music, image display of a photograph, e.g., playback of a moving image. In order to make it possible for a user to use such functions comfortably, input operations by the user have become advanced and complicated. For example, there are electronic apparatuses provided with a cross-shaped key indicating in up, down, right, and left directions for instructing a cursor move, e.g., or a multi-directional key capable of operations in diagonal directions.
In some of the electronic apparatuses capable of such advanced operation, for example, an input operation on a diagonal move by a cross-shaped key is received by a cross-shaped key having four electrical contact points in up, down, right, and left directions, respectively. When a user presses such a cross-shaped key in a diagonal direction, two contacts adjacent to a position physically pressed are detected among contact points in the four directions. For example, if the user presses the key in an upper right direction, the up and the right contact points are detected.
In an electronic apparatus disclosed in Japanese Laid-open Patent Publication No. 2001-351476, for example, a structure has been disclosed of a multi-directional switch in which four contact points are added, and individual inputs in diagonal directions are allocated to the added four contact points, respectively, so that a multi-directional input is allowed. The multi-directional inputs are, for example, inputs in eight directions.
In the above-described electronic apparatus capable of multi-directional operations using the four contact points, a user brings two contact points into contact out of the contact points in the up, down, right, and left directions by pressing a place at which there is no contact point with no operational feeling. Accordingly, the user tries to press the two contact points in a direction having no contact point in order to make connections on the two contact points at the same time. Thus, in the above-described electronic apparatus having the four contact points, there is a problem in that the operation is troublesome and unstable for the user.
There is an improved technique which allows a user to easily perform operations in diagonal directions by achieving a multi-directional switch structurally. However, in the multi-directional switch structurally, contact points are provided to be specifically allocated to points of contact in a key-matrix circuit, or signals of points of contact in a key-matrix circuit are input into a control unit as direct interrupt signals, for example. Accordingly, in an electronic apparatus provided with that switch, there are problems that cause occupation of a few key-matrix circuits, and an increase in the number of signal lines, for example, which results in expansion of a circuit size.